Microorganism culturing assembly



June 10, 1969 P. A. ROHDE MICROORGANISM CULTURING ASSEMBLY Filed Aug. 22, 1967 EVE/26 INVENTOR Pflfll. A ROf/DE BY 1 M, l? Q iTTiZNEYS United States Patent US. Cl. 195-439 1 Claim ABSTRACT OF THE DISCLOSURE A sterile, disposable culturing assembly having a prepared, ready to inoculate culture medium within a cul ture flask; the flask having a wall laterally offset with respect to the opening or mouth of the flask to provide a recess for positioning the culture medium therein, the laterally oifset wall having a relatively flat panel permitting culturing of the microorganisms in a horizontal plane and eliminating the need for angle adjusting shelves for accommodation of culture tubes having solidified slants; the configuration of the walls of the flask permitting access to all portions of the culture medium surface through the opening; and a threaded cap having a resilient member for sealing the opening to prevent loss of moisture from the culture medium over prolonged periods of storage.

Background of the invention Many types of assemblies are presenly employed for culturing microorganisms, for example, Petri dishes of various types and configurations, culture tubes having either a liquid culture medium disposed therein or a solidified medium in the form of a slant, or culture bottles sealed with a resilient stopper having disposed therein a solidified culture medium with a liquid medium and having a desired atmosphere for culturing specified types of microorganisms. Although these assemblies are useful for culturing microorganisms, there are many disadvantages encountered when employing such assemblies. Petri dishes require a relatively freshly prepared solidified culture medium since the medium tends to dry out and form cracks and pull away from the sides of the Petri dish upon prolonged storage. Also, the cover for the Petri dish is generally loosely fitted thereon and requires care when transporting same.

When culture tubes are used containing a liquid medium, the tubes must remain in a vertical position with care taken not to spill any of the inoculated medium over a work surface or where a solidified medium is used, the tube must be positioned at an angle so as to form a slant having a relatively large surface for inoculation with a microorganism.

When culture bottles are used, for example, a diphase bottle which contains a solidified culture medium adhered to a side wall together with a liquid culture medium, the bottle is generally provided with a suitable atmosphere for culturing a desired microorganism and is provided with a resilient, pierceable stopper so as to maintain the desired atmosphere within the bottle. The medium is inoculated by means of a hypodermic syringe rather than a transfer wire loop which is generally employed when culturing microorganisms in standard culture assemblies described above.

Summary of the invention My invention generally contemplates providing a sterile, disposable microorganism culturing assembly comprising a flask having top and bottom walls, a pair of side walls of lesser width than the top and bottom walls, a rectangular closed wall and an open end in the form of a tubular neck having a diameter substantially smaller than the vertical and horizontal axes of the flask, the walls and neck being integrally connected together with the side walls tapering arcuately inwardly to merge with the sides of the neck, and the top and bottom Walls curving arcuately inwardly adjacent the open end of the flask so as to merge with the top and bottom portions of the neck. The bottom wall is formed having a relatively broad flat panel extending through the major portion thereof to provide a base to firmly support the assembly and the bottom wall also being laterally offset in an outward direction from the projected longitudinal axis of the tubular neck a "greater distance than the top wall so as to provide an offset recess in the lower portion of the flask extending for the major portion of the length of the bottom wall. The formed recess provides a space whereby a solidified culture medium may be disposed therein, the culture medium being formed having a flat surface spaced from the longitudinal axis of the neck approximately the same distance as the inner surface of the bottom wall merging with the bottom of the neck. The arcuate curved portions of the side walls merging with the neck and being so curved and tapered that a loop extending through the neck may have access to substantially all portions of the surface of the culture medium. The opening of the flask having means thereon for receiving a cap having a resilient sealing element therein engageable with the outer surface of the neck so as to seal the culture assembly and prevent loss of moisture of the culture medium upon prolonged storage of the assembly.

Description of the drawings In the accompanying drawings illustrating the invention herein,

FIG. 1 is an exploded side elevational view of the culturing assembly;

FIG. 2 is a side elevational View of the culturing assembly having the cap mounted thereon;

FIG. 3 is a plan view in elevation of the culturing assembly;

FIG. 4 is a sectional side elevational view of the assembly of FIG. 2; and

FIG. 5 is a cross-sectional View in elevation taken on the lines 55 of FIG. 4.

In the drawings and referring particularly to FIG. 4, the sterile, disposable microorganism culturing assembly comprises a flask or container 10 having top and bottom walls 12 and 14 and a pair of similar side walls 16 of lesser width than the top or bottom walls 12 and 14. A rectangular closed end wall 18 which is formed integrally with the top, bottom and side walls to form a closed end of the flask 10. A tubular neck 20 is formed at the other end of the flask and is provided with a diameter which is substantially smaller than the vertical and horizontal axes of the flask with the side walls 16 tapering arcuately inwardly as shown most clearly in FIG. 3, and top and bottom walls 12 and 14 curving arcuately inwardly as shown most clearly in FIGS. 2 and 4, so as to merge with neck 20. The flask is formed of a transparent material inert to culture media and microorganisms to be cultured; for example, glass or any suitable plastic material which is transparent, relatively rigid and inert to the culture media and microorganisms, such as polymethylmethacrylate and polystyrene.

Tubular neck 20 is formed having threads 22 for receiving threaded cap member 24. A resilient liner 26 is disposed in cap 24 so as to sealingly engage the outer rim portion 27 of neck 20 so as to seal flask 10 when not in use.

Any desired culture medium C may be disposed in flask 10 as shown in broken lines in FIGS. 4 and 5. Bottom wall 14 is laterally oifset from the longitudinal axis of neck 20 a greater distance than the top wall of flask 10 so as to form a recess for culture medium C. The recess is sutficient to provide the necessary amount and proper depth of culture medium C for culturing microorganisms.

Description of the preferred embodiment When employing a culturing assembly of the type set forth herein, the culture medium may be freshly prepared and disposed in the recess and thereafter the entire assembly sterilized in the usual manner, such as by autoclaving or gaseous sterilization. Where the culture medium, culture flask and cap are in sterile form, the medium will be disposed in the recess using sterile techniques.

The culture flask is positioned on a flat surface with bottom wall 14 lying in a horizontal plane so that the upper surface of the culture medium will be parallel to the bottom wall, as seen most clearly in FIG. 4. Thereafter, culture medium C is inoculated with a microorganism to be cultured employing general techniques common to the art, for example, a wire transfer loop tipped with the microorganism to be cultured.

As described above, the configuration of the flask is such that the wire loop contacts substantially the entire surface of the culture medium. Thereafter, the cover or cap 24 may be loosely threaded on neck 20 and the culturing assembly placed in a thermal environment for growth of the microorganisms, or the cap 24 may be removed entirely. If the organism to be cultured is aerobic, then the thermal atmosphere will be maintained having an oxygen atmosphere. If the microorganism to be cultured is anaerobic, then the thermal atmosphere will be maintained having no oxygen present.

The above assembly is particularly suited for culturing bacteria which are pathogenic, for example, the genus Mycobacterium, which includes pathogenic organisms, causing tuberculosis, the varieties being hominis, patho genic to man; bovis, pathogenic to animals, such as cattle; and avian, pathogenic to birds. An example of a type of culture media which is suitable for culturing Mycobacterium organisms is Lowenstein-Jensen Medium. The species of this genus are aerobes and will grow in the presence of oxygen.

The Clostridium bacilli are anaerobic sporulating bacilli and include the organisms causing tetanus, gas gangrene, food poisoning and others. A typical medium employed for organisms of this type is Trypticase Soy Agar. Sabourand-Dextrose Agar is especially suited for culturing fungi, both pathogenic and non-pathogenic.

It is apparent from the description that the invention as set forth herein provides an improved sterile, disposable culturing assembly which may be discarded after a single use. The configuration of the culture flask is such as to facilitate the inoculation of the entire culture media surface and permits culturing the inoculated media in a horizontal plane. Also, the configuration is such that the culture flask permits stacking in a partitioned rack within an incubator thereby conserving space for culturing other microorganisms.

It is obvious that many changes and variations in the design and configuration of the culture flask and use of various types of culture media may be employed without departing from the spirit of the invention as set forth in the appended claim.

I claim:

1. A sterile, disposable microorganism culturing assembly comprising: an elongated flask being formed of a transparent material inert to culture media and microorganisms to be cultured therein and having top and bottom walls, a pair of similar side walls of lesser width than the top and bottom walls, a rectangular closed end wall and an open end in the form of an externally threaded tubular neck having a diameter substantially smaller than the vertical and horizontal axes of the flask, the walls and neck being integrally connected together, the side walls tapering arcuately inwardly to merge with the sides of the neck and the top and bottom walls curving arcuately inwardly adjacent the open end of the flask so as to merge with the top and bottom of the neck with the bottom wall having a relatively broad flat panel extending through the major portion thereof to provide a base to firmly support the assembly and the bottom wall also being laterally offset in an outward direction from the projected longitudinal axis of the tubular neck a greater distance than the top wall so as to form an offset recess in the lower portion of the flask extending for the major portion of the length of the bottom wall, an internally threaded cap having a sealing portion therein engageable with the externally threaded neck to provide sealing engagement with the open end, and a culture medium disposd in the offset recess with its upper surface being spaced from the projected longitudinal axis approximately the same distance as the inner surface of the top wall, the arcuate curved portions merging the walls with the neck being so curved and tapered that a microorganism transfer loop extended through the neck may have access to substantially all portions of the surface of the culture medium.

References Cited UNITED STATES PATENTS 2,992,974 7/1961 Belcove et al 195139 3,232,495 2/1966 Schneider 215l 3,362,530 1/1968 Johnson 215l ALVIN E. TANENHOLTZ, Primary Examiner.

US. Cl. X.R. 2l5-1 

